Valve cooling and noise suppression

ABSTRACT

Certain embodiments provide a cover mounted on top of a manifold, the cover comprising an exhaust opening and an inner surface forming a space between the inner surface of the cover and an outer surface of the manifold, wherein the space is configured to receive pressurized gas at an inlet positioned on a first side of a valve. The valve is coupled to the outer surface of the manifold and positioned within the space. The exhaust opening is positioned on a second side of the valve opposite the first side of the valve such that pressurized gas circulates from the inlet around the valve and exits through the exhaust opening.

PRIORITY CLAIM

This application claims the benefit of priority of U.S. ProvisionalPatent Application Ser. No. 62/837,801 titled “VALVE COOLING AND NOISESUPPRESSION,” filed on Apr. 24, 2019, whose inventors are Jiansheng Zhouand Craig Fritch, which is hereby incorporated by reference in itsentirety as though fully and completely set forth herein.

TECHNICAL FIELD

The present disclosure relates generally to valve cooling and noisesuppression.

BACKGROUND

Vitreo-retinal procedures may include a variety of surgical proceduresperformed to restore, preserve, and enhance vision. Vitreo-retinalprocedures may be appropriate to treat many serious conditions of theback of the eye. Vitreo-retinal procedures may treat conditions such asage-related macular degeneration (AMD), diabetic retinopathy anddiabetic vitreous hemorrhage, macular hole, retinal detachment,epiretinal membrane, CMV (Cytomegalovirus) retinitis, and many otherophthalmic conditions.

The vitreous is a normally clear, gel-like substance that fills thecenter of the eye. It may make up approximately two-thirds of the eye'svolume, giving it form and shape before birth. Certain problemsaffecting the back of the eye may require a vitrectomy, or surgicalremoval of the vitreous. Removal of vitreous can involve a vitrector(also referred to as the “cutter” or “vitreous cutter”), that works likea tiny guillotine, with an oscillating microscopic cutter to remove thevitreous gel in a controlled fashion. The cutter is powered by apneumatic vitrectomy machine including one or more pneumatic valves(also referred to as drive valves). In certain cases, one or more of thepneumatic valves may be operated at both a very high input voltage andat high speed. Operating a pneumatic valve at such high input voltageand speed, however, causes the pneumatic valve to heat up excessivelyand generate very loud noises.

BRIEF SUMMARY

The present disclosure relates generally to valve cooling and noisesuppression.

Certain embodiments provide a cover mounted on top of a manifold, thecover comprising an exhaust opening and an inner surface forming a spacebetween the inner surface of the cover and an outer surface of themanifold, wherein the space is configured to receive pressurized gas atan inlet positioned on a first side of a valve. The valve is coupled tothe outer surface of the manifold and positioned within the space. Theexhaust opening is positioned on a second side of the valve opposite thefirst side of the valve such that pressurized gas circulates from theinlet around the valve and exits through the exhaust opening.

The following description and the related drawings set forth in detailcertain illustrative features of one or more embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings depict only examples of certain embodiments of thepresent disclosure and are therefore not to be considered as limitingthe scope of this disclosure.

FIG. 1 illustrates an embodiment of a surgical console for apneumatically powered ophthalmic surgical machine, in accordance withcertain embodiments.

FIGS. 2A and 2B illustrate a schematic of a pneumatic system for apneumatically powered vitrectomy machine, in accordance with certainembodiments.

FIG. 3 illustrates the cutting device of a surgical probe;

FIGS. 4A and 4B illustrate a redundant pneumatic circuit in a primarymode and a backup mode respectively, in accordance with certainembodiments.

FIG. 5 illustrates a cross-sectional view of an example cover that ismounted on top of a manifold in which a pneumatic system isincorporated, in accordance with certain embodiments.

FIG. 6 illustrates a top cross-sectional view of an isolation valve, asingle pneumatic valve, and cover, all mounted on top of the manifold ofFIG. 5, in accordance with certain embodiments.

FIG. 7A illustrates a three-dimensional view of the cover of FIG. 5mounted on top of a manifold, in accordance with certain embodiments.

FIG. 7B illustrate a three-dimensional view of a dome shaped covermounted on top of a manifold, in accordance with certain embodiments.

FIG. 8 illustrates an example inlet port that is slotted, in accordancewith certain embodiments.

FIG. 9 illustrates example inlet ports that are arranged next to eachother, in accordance with certain embodiments.

FIG. 10 illustrates multiple example inlet ports with different openingwidths, in accordance with certain embodiments.

FIG. 11 illustrates example tubes coupled to exhaust ports of apneumatic valve and an isolation valve for cooling purposes, inaccordance with certain embodiments.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe drawings. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

While features of the present invention may be discussed relative tocertain embodiments and figures below, all embodiments of the presentinvention can include one or more of the advantageous features discussedherein. In other words, while one or more embodiments may be discussedas having certain advantageous features, one or more of such featuresmay also be used in accordance with various other embodiments discussedherein. In similar fashion, while exemplary embodiments may be discussedbelow as device, instrument, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, instruments, and methods.

FIG. 1 illustrates an embodiment of a surgical console 101 for apneumatically powered ophthalmic surgical machine. The surgical console101 may be configured to drive one or more pneumatic tools 103. Thetools 103 may include, for example, scissors, vitrectors, forceps, andinjection or extraction modules. Other tools 103 may also be used. Inoperation, the pneumatically powered ophthalmic surgery machine of FIG.1 may operate to assist a surgeon in performing various ophthalmicsurgical procedures, such as a vitrectomy. A compressed gas, such asnitrogen, may provide the power through the surgical console 101 topower tools 103. The surgical console 101 may include a display 109 fordisplaying information to a user (the display may also incorporate atouchscreen for receiving user input). The surgical console 101 may alsoinclude a fluidics module 105 (e.g., to support irrigation/aspirationfunctions) and one or more port connectors 107 for coupling to tools 103(e.g., coupling through pneumatic lines attached to the tools 103).

FIGS. 2A and 2B illustrate a schematic of a pneumatic system for apneumatically powered vitrectomy machine. As seen in FIGS. 2A and 2B,the pneumatic system may include a pneumatic valve 217 coupling apressure source 209 (e.g., a regulated pressure source such as a gascylinder or a wall outlet gas supply) to output port A 213 and outputport B 215 (the output port A 213 and output port B 215 may be coupledto the tool 103 through one or more port connectors 107). In someembodiments, the pneumatic valve 217 may be controlled by controller205. In some embodiments, the pressure of the pressure source 209 mayalso be regulated by controller 205 or a separate controller (e.g.,internal to the surgical console 101). The controller 205 may regulatepressure (e.g., to balance between lower pressures for reducing gasconsumption and higher pressures for faster cut rates and/or to increasea dynamic range of available cut rates). In some embodiments, thecomponents of the pneumatic system may be incorporated in one or moremanifolds (e.g., machined out of a metal, such as aluminum) or manifoldplates. The manifolds may be gas tight, and include various fittings andcouplings, and be capable of withstanding relatively high gas pressures.The manifolds may be manufactured as individual pieces or they may bemanufactured as a single piece. In various embodiments, the componentsof the pneumatic system (e.g., in the manifold) may be incorporatedinside the surgical console 101.

The valve 217 may include a solenoid that operates to move the valve 217to one of the two positions (e.g., see FIGS. 2A-B) as directed bycontrol signals from controller 205. In a first position, pneumaticvalve 217 may allow pressurized gas to pass through pneumatic valve 217to output port B 215 to provide pneumatic power to the probe cutter 225while venting pressurized gas from output port A 213 through an exhaustport 227. In a second position, the pneumatic valve 217 may providepressurized gas to output port A 213 and vent pressurized gas fromoutput port B 215 through the exhaust port 227. In this position,pressurized gas may pass through output port A 213 to provide pneumaticpower to a tool 103 (e.g., probe cutter 225). Thus, when the pneumaticvalve 217 is in the first position, the first chamber 229 of the dualchambers 223 may be charged while the second chamber 231 may bedischarged. When the pneumatic valve 217 is in the second position, thesecond chamber 231 may be charged while the first chamber 229 may bedischarged. Note that in the pneumatic system shown in FIG. 2A only asingle pressure sensor 211 is used while in the pneumatic system shownin FIG. 2B two pressure sensors 212 a and 212 b are used. Also, althoughan isolation valve is not shown in FIGS. 2A and 2B, in certain aspects,an isolation valve may be coupled to pneumatic valve 217 to providepressurized gas to pneumatic valve 217 or stop the flow of pressurizedgas to pneumatic valve 217.

As seen in FIG. 3, the probe cutter 225 may act as a cutting device. Theprobe cutter 225 may reciprocate inside an outer tube 303 with a cutterport 301 (e.g., the probe cutter 225 may be moved by a diaphragm 221that in turn oscillates as pressurized gas is alternately directed tooutput ports A and B (and into respective chambers of the dual chamber223)). In some embodiments, probe cutter 225 may be attached to outputports A and B through tube 219 (separate tubes for each port may also beused). As the probe cutter 225 moves back and forth, the probe cutter225 may alternately open and close cutter port 301 with a sharpened tipof the probe cutter 225. Each cycle of the probe cutter 225 throughouter tube 303 may cut through material such as vitreous in the cutterport 301 as the probe cutter 225 is closing. A port duty cycle (PDC) mayindicate the amount of time the cutter port 301 is open and closed. Forexample, a PDC of 49% may indicate the cutter port 301 is open 49% ofthe cycle time (and closed 51% of the cycle time-the cycle time being,for example, the amount of time between each successive opening of thecutter port 301).

In some embodiments, the valve duty cycle (VDC) may include the amountof time the pneumatic valve 217 is in the first and second positions. Insome embodiments, a cut rate of the probe cutter 225 may be controlledby the controller 205 through valve 217. For example, to provide a 2500cuts per minute probe rate, controller 205 may direct pneumatic valve217 to provide pressurized gas alternately to port A (second channel)and port B (first channel) at a rate of approximately 24 milliseconds(ms) per cycle. To obtain a cut rate of 2500 cuts per minute, the twopneumatic channels may cycle open/closed every 24 ms (2500 cuts/min or 1min/2500 cuts*60 seconds/1 min=0.024 seconds/cut=24 ms/cut), which mayopen for 12 ms to each channel.

For the benefit of reducing traction (which can cause retinaldetachment) during vitrectomy procedure, the vitrectomy probe is desiredto be operated at high speed. The common understanding is the faster thebetter. Therefore pneumatic valve 217 is often operated at its maximumspeed (in CPM). At very high speed, each valve cycle time is very short,which requires the solenoid valve to move very fast in opening andclosing. For example, at 15,000 cpm with 50% VDC, in each valve cyclethe time duration of valve open and close is only 2 ms. Therefore thesolenoid valve has to actuate very fast so that it opens and closes inless than 2 ms.

In some cases, increasing solenoid power by coil design and/or applyinghigher voltage along with a stronger return spring can speed up thevalve actuation. However, increasing speed can reduce the reliability ofpneumatic valve 217. This is because as the number of valve cyclesincreases over a given time period, the valve operating condition mayworsen at higher speeds due to higher mechanical impact as well as heatthat is generated by the solenoid coil. In other words, the usage lifeof the pneumatic valve 217 can be reduced when it is operated at higherspeed (in CPM).

To enhance reliability of vitrectomy instruments, in certain cases, aredundant pneumatic circuit may be used, which provides a backuppneumatic valve (BPV). As such, when the primary pneumatic valve, suchas pneumatic valve 217, fails or malfunctions, the system automaticallyswitches to the backup pneumatic circuit, which operates the BPVinstead.

FIG. 4A illustrates a redundant pneumatic circuitry 400 including aprimary pneumatic valve (PPV) 420 in operation and a backup pneumaticvalve (BPV) 430 that can be engaged to power a vitrectomy probe 480 whenthe PPV 420 fails. The redundant pneumatic circuitry 400 includes asource of regulated pneumatic pressure 405 (e.g. compressed gascanister, hospital wall gas, etc.) and tubing 401, 402, 403, 404, 406,407, 408, 409, and 411 for fluidly coupling the components of theredundant pneumatic circuitry 400 with the vitrectomy probe 480.

The source of regulated pneumatic pressure 405 is fluidly coupled withan isolation valve 410 via tubing 401. As shown in FIG. 4A, theisolation valve 410 is a four-way valve. The isolation valve 410 isfluidly coupled (via tubing 402, 403) to a PPV 420 and a BPV 430. Also,each of the PPV 420 and the BPV 430 are fluidly coupled (via tubing 404,406, 407, and 408) to both of a first circuit selection valve 440 and asecond circuit selection valve 450.

The first circuit selection valve 440 and the second circuit selectionvalve 450 are respectively coupled (via tubing 409, 411) to a firstchamber 485 and a second chamber 490 of the vitrectomy probe 480. Thefirst chamber 485 and the second chamber 490 are separated by adiaphragm 495 which is alternatively displaced when one of the PPV 420or the BPV 430 alternatively drive and vent the chambers 485, 490. Thediaphragm 495, in turn, drives the probe cutter 475 in a mannerdescribed above. The redundant pneumatic circuitry 400 includes exhaustports 421, 422, 423 which vent pressurized fluid to atmosphere.

In this detailed description, the terms “off” and “on” in the context ofthe valves state are used as a convenience; however, the description ofthe valve states as “on” and “off” should not be read to implyfunctionality, non-functionality, etc.

Prior to a vitrectomy procedure, the isolation valve 410, the firstcircuit selection valve 440, and the second circuit selection valve 450are all in an “off” state. When these valves are in an “off” state, theflow of the pneumatic pressure is suppressed from being delivered to thevitrectomy probe 480 by virtue of the isolation valve 410 delivering thepneumatic pressure through the BPV 430 and to the first and secondcircuit selection valves 440, 450, which block the flow of fluid intheir “off” state from BPV 430.

At the initiation of a vitrectomy procedure, the inlet isolation 410valve is actuated and put into an “on” state, which supplies pneumaticflow and pressure to the PPV 420. The PPV 420 cycles on/off at aspecific rate (i.e. cuts per minute or CPM) and with specific valve dutycycle (VDC) determined by the user and system control software. Thefirst and second circuit selection valves 440, 450 remain in their “off”state, which allow pneumatic flow and pressure from the PPV 420 to gothrough the first and second circuit selection valves 440, 450 and torespective chambers 485, 490 of the vitrectomy probe 480 and causes theprobe cutter 475 to cut at the specified CPM.

The redundant circuitry 400 also includes two pressure sensors 460, 470and one or more system controllers. The pressure sensors 460, 470monitor pressure of the two channels of tubing 409, 411 in real time andthe system controller receives and processes the pressure data in realtime. The system controller can determine when the pressure is normal orabnormal by a variety of methods. For example, in some cases, the systemcontroller can determine whether or not the pressure is normal byexamining a differential pressure between channels monitored by the twopressure sensors 460, 470.

The system controller can examine the monitored channel pressures,calculate a differential pressure as the pressure from second pressuresensor 470 minus the pressure from the first pressure sensor 460, andreport the differential pressure as being abnormal when the differentialpressure exceeds a particular predetermined threshold. One particularmethod involves comparing peak open pressure and peak close pressure inthe form of differential pressure as a second channel minus a firstchannel to normal open threshold and normal close thresholdrespectively. The system controller can report the pressure as normalwhen both absolute values of peak open pressure and peak close pressureare beyond the absolute values of normal open threshold and normal closethreshold respectively. In this state of operation, the systemcontroller allows the PPV 420 to continue to operate.

Conversely, if the system controller determines that the pressure isabnormal, the system controller can perform one or more remediation stepin an attempt to adjust the pneumatic pressure back to an acceptablelevel. For example, the system controller can adjust primary drive 420valve's duty cycle (VDC) to shift the peaks of open pressure and closepressure up or down. After performing the remediation step, the systemcontroller can examine the pneumatic pressure from the pressure sensors460, 470 and determine if the remediation step was successful. Forexample, if the VDC adjustment successfully brings the absolute valuesof peak open pressure and peak close pressure beyond the absolute valuesof normal open threshold and normal close threshold respectively, thesystem controller determines that the remediation step was successfuland causes the PPV 420 to maintain operation. Conversely, when thesystem controller determines that the remediation step was unsuccessful,the system controller can cause the redundant circuitry 400 to switchthe vitrectomy to a backup mode by switching to the BPV 430.

FIG. 4B illustrates the redundant pneumatic circuitry 400 with the BPV430 engaged for powering the vitrectomy probe 480 after the systemcontroller determines that PPV 420 failed. When the system controllerswitches the redundant pneumatic circuitry to the BPV 430, the inletisolation valve is actuated and put into an “off” state, which suppliespneumatic flow and pressure to the BPV 430. The BPV 430 cycles on/off ata specific rate (i.e. cuts per minute or CPM) and with specific valveduty cycle (VDC) determined by the user and system control software.Also, the system controller actuates the first and second circuitselection valves 440, 450 to their “on” state, which allow pneumaticflow and pressure from the BPV 430 to go through the first and secondcircuit selection valves 440, 450 and to respective chambers 485, 490 ofthe vitrectomy probe 480 and causes the probe cutter 475 to cut at thespecified CPM.

The pressure sensors 460, 470 can continue to monitor pressure of thetwo channels of tubing 409, 411 in real time and the system controllercan continue to receive and process the pressure data in real timewithout interruption caused by the switch to backup mode. The systemcontroller can determine when the pressure is normal or abnormal by avariety of methods. For example, in some cases, the system controllercan determine whether the pressure is normal by examining a differentialpressure between channels monitored by the two pressure sensors 460,470.

The system controller can processes the pressure data of the twopressure sensors and determine when the pressure is normal or not, e.g.comparing peak open pressure and peak close pressure in the form ofdifferential pressure as the second channel minus the first channel tonormal open threshold and normal close threshold respectively. When thepressure is normal, the system controller can cause the BPV 430 tocontinue to operate. When the pressure is abnormal, the systemcontroller can perform another remediation step, e.g. adjusting backupdrive 430 valve's duty cycle (VDC) to shift the peaks of open and closepressure up or down. When the remediation step is successful in bringingthe pressure back to normal, the system controller can cause the BPV 430to maintain operation. When the remediation step is unsuccessful inbringing the pressure back to normal, the system controller candetermine that an unresolvable system fault has occurred, and the systemcontroller can shut down vitrectomy operation.

In addition, since the BPV 430 maintains the same vitrectomy operationas the PPV 420, the vitrectomy procedure is not interrupted or stoppedand the service to resolve the PPV 420 failure or malfunction is noturgent.

Regardless of whether a BPV is used to provide redundancy, operating apneumatic valve at a high valve cycle rate may cause the pneumatic valveto overheat and generate loud noise. For example, applying a highvoltage to the solenoid coil within the pneumatic valve may cause thesolenoid coil to excessively overheat and to actuate the correspondingsolenoid plunger faster, which generates a much louder noise.Accordingly, certain embodiments described herein provide an exhaustcooling and muffler cover (“cover”) for cooling a pneumatic valve'stemperature using pressurized gas vented from the pneumatic valve'sexhaust port while suppressing the noise associated with solenoidplunger and venting of the pressurized gas. In cases where a pneumaticsystem involves a redundant pneumatic circuitry with an insulation valveas well as a backup valve, certain embodiments described herein providea cover for covering both the primary and the backup pneumatic valvesand/or the isolation valve, as shown in FIGS. 5-10. In such embodiments,the pressurized gas cools both the pneumatic valve(s) and the isolationvalve.

FIG. 5 illustrates a cross-sectional view of an example cover 520 thatis mounted on top of manifold 532 in which a pneumatic system isincorporated. The pneumatic system described in relation to FIG. 5involves a redundant pneumatic circuitry including an isolation valve510, a PPV 517 and a BPV, which is not shown for simplicity. Also, therest of the components of the redundant pneumatic circuitry, asdescribed in relation to FIGS. 4A-4B, are not shown in FIG. 5 forbrevity and simplicity. Cover 520 may comprise one or more plastic,metal, foam, rubber, or similar material.

As described above, operating PPV 517 at a high valve cycle rate maycause the pneumatic valve to overheat and generate loud noise. Cover 520is configured to circulate pressurized gas around the exterior of PPV517 and isolation valve 510 for cooling purposes. In one example, thepressurized gas is provided through an inlet port 528 at one end of anexhaust pathway 526 that connects to an exhaust port 524 associated withPPV 517. In certain embodiments, inlet port 528 is created by drillingthrough manifold 532 and creating exhaust pathway 526 to connect inletport 528 and exhaust port 524. Inlet port 528 may have different shapes(e.g., circular, linear, etc.) and sizes in different embodiments. Incertain embodiments, instead of a single inlet port, multiple inletports may be used. FIGS. 8-10 show some example variations of thedifferent shapes, sizes, numbers of inlet ports. An inlet port may alsobe referred to as an aperture.

Exhaust port 524 refers to an exhaust port of (e.g., exhaust port 422 ofFIGS. 4A-4B) PPV 517 through which PPV 517 releases pressurized gas.Cover 520 is shaped such that pressurized gas, venting through inletport 528 and into the space underneath cover 520, circulates around PPV517 and isolation valve 510 and, thereby, cools PPV 517 and isolationvalve 510. The space underneath cover 520 is formed by the inner surfaceof cover 520 (e.g., inner surface of all sides of cover 520) and theouter surface of manifold 532. The outer surface of manifold 532 refersto an area of the manifold that is covered by cover 520.

As shown, cover 520 also comprises an exhaust opening 522 to allow thepressurized gas to exit from the space underneath cover 520. In certaincases, pressurized gas exiting exhaust opening 522 creates undesirednoise. As such, in some embodiments, cover 520 as well as exhaustopening 522 are shaped such as to reduce or suppress the generatednoise. Additionally, one or more components (e.g., filtering material)may be placed outside of exhaust opening 522 to further reduce noise.For example, a component may be positioned outside of exhaust opening522 to cover the opening. An example of a component that may be usedoutside of exhaust opening 522 may include open cell foam, reticulatedfoam, metal screen/mesh, perforated metal/plastic, sinteredmetal/plastic, (filter) paper, etc.

In one example, exhaust opening 522 refers to a rectangular opening atthe bottom of one of the sides of cover 520, shown as side 521. Side 521faces another side 519 of cover 520. Inlet port 528 is positionedbetween side 519 and PPV 517. In other examples, exhaust opening 522 mayrefer to other types of openings with other shapes in other areas ofcover 520. In certain embodiments, the shape and size of exhaust opening522 are designed to allow exhaust opening 522 to gradually slow thespeed of the expanding gas in order to reduce the noise level associatedwith the pressurized gas. Also, cover 520 is configured to act as amuffler by allowing the pressurized gas exiting from inlet port 528 toexpand, thereby attenuating the gas's pressure. In some embodiments, thecover 520 also suppresses noise generated by mechanical movement oractuation of the solenoid valves inside by enclosing such a noise sourcewith noise absorbing materials. Note that although a single exhaustopening 522 is shown in FIG. 5, in certain embodiments, cover 520 maycomprise multiple exhaust openings. In addition, the size, shape, andlength of the exhaust opening may vary in different embodiments.

Cover 520 also comprises one or more fasteners for mounting cover 520 tomanifold 532. An example of a fastener is shown in FIG. 5 as fastener530, which may be screwed to manifold 532. A top view of fastener 530 isshown as fasteners 530 a and 530 b in FIG. 6.

Although in FIG. 5 exhaust port 524 refers to an exhaust port of PPV517, in certain embodiments, exhaust port 524 represents a shared outletfor the exhaust ports of PPV 517 (e.g., exhaust port 422 of PPV 420FIGS. 4A-4B) as well as a BPV (e.g., exhaust port 423 of BPV 430 FIGS.4A-4B), which may be positioned under cover 520 with PPV 517. In otherwords, in such an example, exhaust port 524 vents pressurized gasexiting through the exhaust ports of PPV 517 and the BPV. In oneexample, pressurized gas exiting from the exhaust ports of PPV 517 andthe BPV may be combined through one or more exhaust pathwaysincorporated into manifold 532. The one or more exhaust pathways maythen intersect at exhaust port 524.

In certain other embodiments, exhaust port 524 represents a sharedoutlet for the exhaust ports of not only PPV 517 and BPV but alsoisolation valve 510. In other words, in such an example, exhaust port524 vents pressurized gas exiting through the exhaust ports of PPV 517and BPV (e.g., exhaust ports 422 and 423 of FIGS. 4A-4B) as well asisolation valve 510 (e.g., exhaust ports 421 FIGS. 4A-4B). Also, in suchan example, pressurized gas exiting from the exhaust ports of isolationvalve 510 and PPV 517 and BPV may be combined through one or moreexhaust pathways that connect all the exhaust ports together.

In another example, exhaust port 524 represents a shared outlet for theexhaust port of isolation valve 510 and the exhaust port of only one ofPPV 517 and BPV (e.g., PPV 420 of FIGS. 4A-4B). Also, although in FIG. 5isolation valve 510 is located under cover 520, in certain embodiments,isolation valve 510 may be outside cover 520. In such embodiments, cover520 may be smaller in size. Also, in certain embodiments, PPV 517 andBPV may both be positioned under cover 520 and, in certain otherembodiments, only a single one of PPV 517 and BPV may be positionedunder cover 520.

Further, FIG. 5 shows a single manifold plate, shown as manifold 532,through which exhaust pathway 526 and inlet port 528 are created (e.g.,by drilling). However, in some embodiments, more than one manifold platemay be used. In such embodiments, an exhaust pathway and an inlet portsimilar to exhaust pathway 526 and inlet port 528 may be created in thetwo manifold plates. For example, in some embodiments, two manifoldplates may be used on top of each other, where a seal may be used inbetween the two plates to ensure that the pressurized gas does notescape an exhaust pathway created in the two manifold plates. In someother embodiments, three manifold plates may be used with a seal betweeneach two plates. In such embodiments, an exhaust pathway and an inletsimilar to exhaust pathway 526 and inlet 528 may be created in themanifold plates.

Although the pneumatic system of FIG. 5 involves a redundant pneumaticcircuitry (e.g., shown in FIGS. 4A-4B), in certain embodiments, a covermay be used for cooling and noise suppression in conjunction with apneumatic system that does not involve a redundant pneumatic circuitry.An example of such a system was described in relation to FIGS. 2A and2B. In such embodiments, a cover, similar to cover 520, is used to cooland suppress any noise generated by a pneumatic valve (e.g., pneumaticvalve 217 of FIGS. 2A-B). More specifically, pressurized gas exitingfrom the pneumatic valve's exhaust port (e.g., similar to exhaust port524) is vented into the space underneath the cover to cool the pneumaticvalve. The pressurized gas then exits the cover's exhaust opening, whichis configured to suppress the noise associated with the pressurized gas.In some embodiments, the cover 520 also suppresses noise generated bymechanical movement or actuation of the solenoid valve inside byenclosing such a noise source with noise absorbing materials. In caseswhere an isolation valve is coupled to the pneumatic valve of FIGS. 2Aand 2B, the isolation valve may also be positioned underneath the cover.In such cases, PPV 517 and isolation valve 510 shown in FIG. 5, andlater in FIGS. 7A-11, may represent pneumatic valve 217 of FIGS. 2A-2Band an isolation valve coupled to pneumatic valve 217, respectively.Note that the embodiments described herein are applicable regardless ofthe number of valves covered by the cover (e.g., cover 520). Forexample, in one example, only a single valve may be covered and in otherexamples, multiple valves (two, three, or more) may be covered. Also,the embodiments described herein are applicable regardless of the typeor functionality of the pneumatic valve(s) and/or isolation valvepositioned under the cover. In other words, although the pneumaticvalve(s) and/or isolation valve described herein are used in conjunctionwith a pneumatically powered ophthalmic surgical machine, theembodiments of the present disclosure are applicable for cooling andnoise suppression associated with any type of pneumatic valve and/orisolation valve used in conjunction with any machines or devices.

FIG. 6 illustrates a top cross-sectional view of an isolation valve 510,a single PPV 517, and cover 520, all mounted on top of manifold 532. Asshown, cover 520 comprises two fasteners 530 a and 530 b for mountingcover 520 to manifold 532. Between PPV 517 and side 519 of cover 520 isan inlet port 528 from which pressurized gas is vented into the spaceunderneath cover 520 for cooling PPV 517 and/or isolation valve 510. Thepressurized gas then exits from an exhaust opening from the other side521 of cover 520. As shown, the distance between inner surface 640 ofside 519 of cover 520 and the side 642 of PPV 517 is configured suchthat the pressurized gas exiting from inlet port 528 is forced to flownear or onto the surface or exterior of PPV 517. The distance, in FIG.6, is shown as distance 629. In one example, distance 629 is one-eighthof an inch. Generally, the distance is large enough to allow for thepressurized gas exiting inlet port 528 to expand such that pressure doesnot build up underneath the cover. The distance is also small enough toensure that the pressurized gas does not expand away from PPV 517.

FIG. 7A illustrates a three-dimensional view of cover 520 that ismounted on top of manifold 532. As shown, cover 520 is a five-sided box,with an open bottom, that is mounted on manifold 532 using fastener 530.The open bottom of cover 520 is configured to receive PPV 517 andisolation valve 510. On its side 521, cover 522 provides an exhaustopening 522 through which pressurized gas exits the space underneathcover 520. Although shown as a box with a rectangular shape, cover 520may have different shapes and sizes. As seen in FIG. 7B, a dome-shapedcover may be used in some embodiments. In some embodiments, the dome maybe an oval-shaped dome.

FIGS. 8-10 illustrate different examples of one or more inlet portsthrough which pressurized gas is vented into the space underneath cover520.

FIG. 8 illustrates an inlet port 828 that is slotted. A slotted inletport 828 may be advantageous from a sound attenuation standpoint byfocusing sound along a single plane or slotted inlet port 828 and/orfrom a cooling standpoint by supplying a solid curtain of air over thevalve 517 and/or from a manufacturing standpoint (e.g., a slotted inletport may be simpler to fabricate than a hole(s)). Although only a singleslotted inlet port 828 is shown in FIG. 8, in certain embodiments,multiple slotted inlet ports may be used.

FIG. 9 illustrates inlet ports 928 that are arranged next to each other.In certain embodiments, all inlet ports 928 are fed from the sameexhaust pathway (e.g., exhaust pathway 526) that connects with theexhaust port associated with PPV 517 and/or isolation valve 510. Notethat the number, size, and shaped of inlet ports 928 may vary indifferent embodiments. Also, in certain embodiments, a combination ofdifferent sizes and shapes of inlet ports may be used. For example, inembodiments where multiple inlet ports are used, one inlet port may beslotted while others may be circular. Using inlet ports 928 may beadvantageous from a sound attenuation standpoint (e.g., the size ofholes or inlet ports 928 can be selected to reduce or break-up the soundcoming out of the passage), and/or from a cooling standpoint (e.g.,inlet ports 928 may provide a precise control of air flow to certainlocations), and/or from a manufacturing standpoint (if less airflow isdesired, then fabricating a small hole or series of holes may beeasier).

FIG. 10 illustrates multiple inlet ports 1028 with different openingwidths. In certain embodiments, all inlet ports 1028 are fed from thesame exhaust pathway that connects with the exhaust port(s) associatedwith PPV 517 and/or isolation valve 510. Using inlet ports 1028 may beadvantageous from a sound attenuation standpoint (e.g., using differenthole sizes in different locations may be more effective for soundattenuation purposes than using a uniform hole size/pattern (e.g., inletports 928)), and/or from a cooling standpoint (e.g., changing theopening width allows more/less air to flow to a certain location).

In certain embodiments, an inlet port, such as the inlet portsillustrated in FIGS. 5-10, may comprise filtering material to suppressnoise. As an example, filtering material may be placed within or on aninlet port. Examples of filtering material may include a screen,perforations, a mesh, an open cell foam, sintered material, etc.

FIG. 11 illustrates an alternative embodiment for cooling PPV 1117 aswell as isolation valve 1110, which are part of a redundant pneumaticcircuitry whose other components are not shown for simplicity. Also,FIG. 11 does not illustrate a manifold on which PPV 1117 and isolationvalve 1110 are mounted. In FIG. 11, exhaust port 1124 of PPV 1117 iscoupled to a tube 1150 that blows pressurized gas exiting from exhaustport 1124 onto the exterior of PPV 1117. Tube 1150 may also be referredto as an exhaust pathway. More specifically, instead of creating anexhaust pathway through one or more manifolds to direct the pressurizedgas exiting from exhaust port 1124 to an inlet port next to PPV 1117, inthe embodiments of FIG. 11, tube 1150 is used to direct the pressurizedgas exiting from exhaust port 1124 onto the exterior of PPV 1117. Incertain embodiments, tube 1150 is not incorporated into the one or moremanifolds while, in certain other embodiments, tube 1150 is incorporatedinto the one or more manifolds on top of which PPV 1117 is mounted. Inone example tube 1150 is a plastic gas tube.

As shown in FIG. 11, exhaust port 1126 of isolation valve 1110 iscoupled to a tube 1152 that blows pressurized gas exiting from exhaustport 1126 onto the exterior of isolation valve 1110. In certainembodiments, tube 1152 is not incorporated into the one or moremanifolds while, in certain other embodiments, tube 1152 is incorporatedinto the one or more manifolds on top of which isolation valve 1110 ismounted. In one example, tube 1152 is a plastic gas tube.

Although in the embodiments of FIG. 11 a separate tube is coupled toeach of the exhaust ports 1124 and 1126 of PPV 1117 and isolation valve1110, in certain other embodiments a single tube may be coupled to bothexhaust ports 1124 and 1126 through a connector element and blowpressurized gas exiting from exhaust ports 1124 and 1126 onto one orboth of PPV 1117 and isolation valve 1110.

Although the pressurized gas exiting tubes 1150 and 1152 are able tocool PPV 1117 and isolation valve 1110, the gas flow creates someundesired noise. As such, in certain embodiments, a cover, similar tocover 520 of FIG. 5, may be used to not only ensure circulation of thepressurized gas around the PPV 1117 and isolation valve 1110, resultingin more effectively cooling the valves, but also suppress the noiseassociated with the exhaust gas. In certain embodiments, the cover alsosuppresses noise generated by mechanical movement or actuation of thesolenoid valves inside by enclosing such a noise source with noiseabsorbing materials. In certain embodiments, the cover is mounted on topof PPV 1117 and isolation valve 1110 with two openings to allow tubes1150 and 1152 to exit the cover and two other openings to allow the tipsof the tubes 1150 and 1152 to enter the cover again. The cover alsocomprises an exhaust opening, similar to exhaust opening 522, to allowthe pressurized gas to exit the space underneath the cover. Inembodiments where the tubes are incorporated into the manifold, thecover may only comprise two openings to allow the tips of tubes 1150 and1152 to enter the cover. The tubes 1150 and 1152 may accordingly act asinlets for gas to the space defined by the cover. Note that an inlet mayrefer to an inlet port (e.g., inlet ports 528, 828, 928. 1028) or a tube(e.g., tube 1150 and 1152).

Note that although the isolation valve (e.g., 510 or 1110) shown inFIGS. 5-11 is an isolation valve that is used in conjunction with aredundant pneumatic circuit, as shown in FIGS. 4A-4B, in certainembodiments, an isolation valve that is positioned under the cover 520described herein may not be an isolation valve that is used in aredundant pneumatic circuitry. For example, in certain cases, anisolation valve may be used in conjunction with a pneumatic system thatdoes not involve a redundant pneumatic circuitry (e.g., FIGS. 2A-2B).Also, in certain embodiments, an isolation valve that is positionedunder the cover 520 described herein may not be a four-way valve, suchas shown in FIGS. 4A-4B. For example, the isolation valve may be athree-way valve or any other type of isolation valve. In other words,the embodiments described herein with respect to FIGS. 5-11 areapplicable regardless of the type and use of an isolation valve that ispositioned under cover 520.

The foregoing description is provided to enable any person skilled inthe art to practice the various embodiments described herein. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments. Thus, the claims are not intended to belimited to the embodiments shown herein, but are to be accorded the fullscope consistent with the language of the claims.

What is claimed is:
 1. A cover mounted on top of a manifold, the covercomprising: an exhaust opening; and an inner surface forming a spacebetween the inner surface of the cover and an outer surface of themanifold, wherein: the space is configured to receive pressurized gas atan inlet positioned on a first side of a valve; the valve is coupled tothe outer surface of the manifold and positioned within the space; andthe exhaust opening is positioned on a second side of the valve oppositethe first side of the valve such that the pressurized gas circulatesfrom the inlet around the valve and exits through the exhaust opening;wherein a second valve is coupled to the outer surface of the manifoldand positioned within the space; wherein: the inlet comprises an inletport, the inlet port is connected to an exhaust port of the valvethrough a passage in the manifold, and the pressurized gas is releasedfrom the valve through the exhaust port.
 2. The cover of claim 1,wherein: the inlet port is positioned between a first side of the coverand the first side of the valve; and a second side of the covercomprises the exhaust opening.
 3. The cover of claim 1, wherein thecover is rectangular in shape with an open bottom, wherein the openbottom of the cover is configured to receive the valve.
 4. The cover ofclaim 1, wherein the cover comprises a dome with an open bottom, whereinthe open bottom of the cover is configured to receive the valve.
 5. Thecover of claim 4, wherein the cover comprises an oval-shaped dome. 6.The cover of claim 1, wherein: the pressurized gas is released from thevalve and the second valve through the exhaust port, the exhaust port isshared between the valve and the second valve.
 7. A cover mounted on topof a manifold, the cover comprising: an exhaust opening; and an innersurface forming a space between the inner surface of the cover and anouter surface of the manifold, wherein: the space is configured toreceive the pressurized gas at an inlet positioned on a first side of avalve; the valve is coupled to the outer surface of the manifold andpositioned within the space; and the exhaust opening is positioned on asecond side of the valve opposite the first side of the valve such thatpressurized gas circulates from the inlet around the valve and exitsthrough the exhaust opening; wherein a second valve is coupled to theouter surface of the manifold and positioned within the space; wherein:the inlet comprises a tube, the tube is connected to an exhaust port ofthe valve, and the pressurized gas is released from the valve throughthe exhaust port.
 8. A pneumatic system, comprising: a tool with a firstchamber and a second chamber on respective sides of a pneumaticallydriven diaphragm for reciprocating a component of the tool; apressurized gas source; a valve coupled to the pressurized gas source,the valve having a solenoid which, when supplied with a current, moves asolenoid plunger to alternatively deliver and vent pressurized gasthrough a first outlet line and a second outlet line which respectivelydeliver and vent pressurized gas to and from the first chamber and toand from the second chamber of the tool; a power supply coupled to thesolenoid of the valve for supplying a voltage to drive a current in thesolenoid; a manifold on top of which the valve is mounted; a covermounted on top of the manifold, wherein the cover comprises: an exhaustopening; and an inner surface forming a space between the inner surfaceof the cover and an outer surface of the manifold, wherein: the space isconfigured to receive the pressurized gas at an inlet positioned on afirst side of a valve; the valve is coupled to the outer surface of themanifold and positioned within the space, and the exhaust opening ispositioned on a second side of the valve opposite the first side of thevalve such that the pressurized gas circulates from the inlet around thevalve and exits through the exhaust opening.
 9. The pneumatic system ofclaim 8, wherein: the inlet comprises an inlet port, the inlet port isconnected to an exhaust port of the valve through a passage in themanifold, and the pressurized gas is released from the valve through theexhaust port.
 10. The pneumatic system of claim 9, wherein: the inletport is positioned between a first side of the cover and the first sideof the valve, and a second side of the cover comprises the exhaustopening.
 11. The pneumatic system of claim 8, wherein the cover isrectangular in shape with an open bottom, wherein the open bottom of thecover is configured to receive the valve.
 12. The pneumatic system ofclaim 8, wherein the cover comprises a dome with an open bottom, whereinthe open bottom of the cover is configured to receive the valve.
 13. Thepneumatic system of claim 12, wherein the cover comprises an oval-shapeddome.
 14. The pneumatic system of claim 8, wherein: the inlet comprisesa tube, the tube is connected to an exhaust port of the valve, and thepressurized gas is released from the valve through the exhaust port. 15.The pneumatic system of claim 8, wherein a second valve is coupled tothe outer surface of the manifold and positioned within the space. 16.The pneumatic system of claim 15, wherein: the inlet comprises an inletport, the inlet port is connected to an exhaust port of the valvethrough a passage in the manifold, the pressurized gas is released fromthe valve through the exhaust port, and the exhaust port is sharedbetween the valve and the second valve.
 17. The pneumatic system ofclaim 8, further comprising an isolation valve and a control system,wherein: the control system is configured to actuate the isolation valveto selectively allow pneumatic pressure to flow to the valve andsuppress pneumatic pressure to a backup valve and suppress pneumaticpressure to flow to the valve and allow pneumatic pressure to the backupvalve, the isolation valve is coupled to the outer surface of themanifold and positioned within the space.
 18. The pneumatic system ofclaim 17, wherein: the inlet comprises an inlet port, the inlet port isconnected to an exhaust port of the valve through a passage in themanifold, the pressurized gas is released from the valve through theexhaust port, the exhaust port is shared between the valve and thesecond valve.